More intake air
Thread Starter
Heel & Toe
Joined: Jan 2003
Posts: 15
Likes: 0
From: ORANGE CITY FLORIDA
More intake air
I've a modified l-98 with a tpis miniram and a 1000 cfm throttle body. My problem is even after modifing my MAF it will only flow about 690 CFM. does anyone know if someone has modified a Granatelli type MAF for better intake flow? :skep:
Thread Starter
Heel & Toe
Joined: Jan 2003
Posts: 15
Likes: 0
From: ORANGE CITY FLORIDA
Re: More intake air (Cooter)
L98 block p&s to 388cu in ported L98 heads 202 int. 160 ex. pace perf. LT4 hot cam. comp cams 1.6 roller rockers, TPIS mini ram intake, Accel 30lb inj'rs, Accel 1000 cfm throttle body, MSD billet dist, MSD-6AL ign control,
2 1/2" true unrestricted dual exh w/ "X" pipe& LT1 mufflers, TPI trans w/3000 rpm conv. 354:1 rear gear
2 1/2" true unrestricted dual exh w/ "X" pipe& LT1 mufflers, TPI trans w/3000 rpm conv. 354:1 rear gear
Team Owner
Joined: Sep 2001
Posts: 62,139
Likes: 1,728
From: Athens AL
C7 of the Year - Unmodified Finalist 2021
C4 of Year Finalist (performance mods) 2019
Re: More intake air (BLUEACE)
I doubt if you need all that CFM of air, but you can switch to a Speed Density setup and you wont have a problem.
Drifting
Joined: Nov 2001
Posts: 1,783
Likes: 2
From: Latham NY
Re: More intake air (BLUEACE)
Here are some MAF flow numbers that have been posted on the forum before:
529 CFM - max. flow rate stock
711 CFM - max. flow rate with screens removed
750 CFM - max. flow rate with screens and cooling fins removed
Here is a carb formula for needed air flow:
(engine CID X max RPM ) divided by 3456 = CFM
You seem to have enough flow with the screens removed. The 1000cfm throttle body seems large and is bigger than the maf will allow.
[Modified by Bluevette85, 9:46 AM 1/4/2003]
529 CFM - max. flow rate stock
711 CFM - max. flow rate with screens removed
750 CFM - max. flow rate with screens and cooling fins removed
Here is a carb formula for needed air flow:
(engine CID X max RPM ) divided by 3456 = CFM
You seem to have enough flow with the screens removed. The 1000cfm throttle body seems large and is bigger than the maf will allow.
[Modified by Bluevette85, 9:46 AM 1/4/2003]
Safety Car
Joined: Dec 2000
Posts: 3,767
Likes: 5
From: Jacksonville Fl
Re: More intake air (BLUEACE)
But...just remember, the Nascar engines run 8-9K RPM 355ci motors that make around 750 HP, all with a 390 CFM restricted carb.
I wouldn't worry about the MAF unless it is causing calibration problems at high flow, since there is an upper flow limit to it's measuring ability.
Usually, people with 400ci or bigger strokers see this kind of problem and end up switching to speed-density systems to completely eliminate the MAF.
[Modified by BBA, 9:40 AM 1/5/2003]
I wouldn't worry about the MAF unless it is causing calibration problems at high flow, since there is an upper flow limit to it's measuring ability.
Usually, people with 400ci or bigger strokers see this kind of problem and end up switching to speed-density systems to completely eliminate the MAF.
[Modified by BBA, 9:40 AM 1/5/2003]
Team Owner
Joined: Dec 2000
Posts: 90,675
Likes: 304
From: SE NY
Cruise-In II Veteran
Re: More intake air (BLUEACE)
I agree with the 785cfm requirement for your 388cid at 7,000rpm, but that assumes 100%VE.
At say 80%-90% VE the max air flow required drops into the 630-710cfm range. Even at a 95% VE the requirement would only be 746cfm, well within the capability of a gutten MAF and 52mm TB.
Since you're reving to 7,000rpm you might benefit from a SLP (or other) ram air set up on your '88 to push more air when you need it.
At say 80%-90% VE the max air flow required drops into the 630-710cfm range. Even at a 95% VE the requirement would only be 746cfm, well within the capability of a gutten MAF and 52mm TB.
Since you're reving to 7,000rpm you might benefit from a SLP (or other) ram air set up on your '88 to push more air when you need it.
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